BY A. B. WALKOM. 



149 



^"HSlX 



W 



The older of these two divi- 

 sions, that on the northern side 

 of the fault, I have called here 

 the Webber's Creek Series. This 

 series has been examined, at in- 

 tervals, for about a distance of 

 10 miles in an E.-W. direction, 

 and extends for quite 5 miles 

 north from the fault, which 

 forms its southern boundary. 

 The series consists of sandstones 

 and shales, with contemporane- 

 ous lava-flows. The sandstones 

 are more of the nature of arkoses, 

 being composed mostly of grains 

 of orthoclase with a smaller 

 amount of quartz, hornblende, 

 § and biotite. In places, in these 

 ^ arkose sandstones, there are 



o 



H small bands of chocolate shale. 



.3 The sandstones are conglomeratic 



"* 3 • 



S in places, and, where this is the 



I case, they contain pebbles of such 

 ^ rocks as banded rhyolite, ande- 

 ^ site, aplitic granite, porphyrite, 

 quartzite, etc. The lava-flows 

 associated with this series con- 

 sist of dacite and hornblende- 

 felspar porphyry. There does 

 not seem to be any doubt but 

 that these flows are contempora- 

 neous and not intrusive, although 

 no very definite evidence is forth- 

 coming on that point. They form 

 long, comparatively narrow out- 

 crops, roughly parallel to the 

 strike of the arkose sandstones, 

 and, being harder than the latter, 



